Concentric intake and exhaust valves for internal combustion engines and the like



July 31, 1956 CONCENTRIC INTAKE AND EXHAUST VALVES FOR INTERNAL Filed March 17, 1954 D E OLSON 2,756,732

COMBUSTION ENGINES AND THE LIKE 2 Sheets-Sheet l INVENTOR.

D. E. OLSON July 31, 1956 CONCENTRIC INTAKE AND EXHAUST VALVES FOR INTERNAL COMBUSTION ENGINES AND THE LIKE 2 Sheets-Sheet 2 Filed March 17, 1954 INVENTOR. flozzaZaflzzmrd 0150/;

United States Patent F v.

2,756,732 CONCENIRIC- INTAKE AND? EXHKUST vmz'vns' 5 FOR INTERNAL COMBUSTION ENGINEs THE LIKE Donald-Edward. 0lso'n; IiakeGenva,-Wi. Application March-:11, 1954; Serial ms-41ers 16"Claims; c1; 1 23- 753 The; present" invention relates to" intake and exhaust valves for internal combustion engine's fand the' like, tt'ian arrangementof intake and exhaust-valvesin concentric" relation and, particularly, to a concentric arrangement df intake and exhaustvalves for four cycle internal cembustion engines: and the like wherein the adrnis's'ioii valve is: relatively freelymounted for movement in response solely "to fluid. pressures acting thereon? In'conventio'nal four cycle internal combustion efigi' therintake, inlet, or admission valveand-th'e exhaust val provided ina-each enginecylinder areboth pop'j iet valvee 25 each comprising." a stern slidably guided I in the en'g i'ne 'i block or rhead-rand a circular valve head for 'cloSihgtlie'j respectiver: port. Both"valves are positively driveii enginetoperate'd' cam means and are n'rirrnally reta d f inclos'ed ositionby very stiff or strong spriiigs 'over e v "f only uponcam actuation of the -'valve's.' In view-of he" fact thatitwo circular ports are provided ineach cy'liiid j it isapparentthat each port 'must' beofa diameter less thanone half ofthe diameter ofthe cylinderunle sssp" ia design is resorted to. In recent'years, progressin meta lurgy', in 'the' petroleum art and in engiriddes'i'gnhas'm cornmodated'long desired incre'as'esinengine compressi ratiosto' as high as-8.25 'to l. In the highfcompressi range, the vsize of the-enginecylincler and comhifs'tion chambermust be decreased in relation to the"amjouiit" 40 gas admitted to-the'- chamber. He'weverfth -necessary; compactness of the combustion cliainberfcarinotbe? tained in'relatio'n' to valve port siz'e'iminany conventional motor designsgsuch asthe L hea'd engine,'"since de 7 in. combustion chamber size necessarily 'leads 'tof a de crease in port size.- This dilemma has practicallyelimif nated theL-hea'dengine from furtherpowerincrea's has'forced engine designers to investigate and 'eX'per with specialized combustion chamber andpistondesig Many designers and manufacturers" havefn ad'o'pt hemisphericalor pill shap'e'd combustion" chambers an take and exhaust valves setat' various angles infth cha bers. By recourse to overheadwalves, angularlyfrelaftd to one-another and to the combustion chamberf and a I V hemispherical combustion chamber; the problem has been eased somewhat. However; even with s uclfdesigjri, a definite limitis'imposedf Each year; des rsfin deavors to increase compression ratios and'engliie po er, are being forced more andmore to departfrorri' theabo design-and to adopt combustioncharrib'e'rsof parabolic shape and to employ domed pistons," Withthe d riie' on the piston progressively increasing in height until design possibilities are exhausted. p r

It is an object'of "the present inventionf'to' provide a 7 novel approachto engine design and, partic'lularly, itoprovide a new approach for the design of e gine -or qcreas a horsepower and increased compression r naabymeai s' of a novel'arrangement of the intake" and'exhans'tvaliie' s in each engine cylinder. v a v Specifically, it is -a pri'mar'y*'object"of the esnr" vention to provide a novel :en'ginevalveand head -o"r block design wherein the engine exhaust port and exhaust valve 2,756,732 Patented J'nlj 3 I, 1' 956' Z Iiiay be I conventional, butwherein the intake or aam sion'jpo'rt' is disposed in generally concentric relatio totliee' au'stport and surrounds the, exhaust port,

v arid wlierein the'ihtake'oradrnission valve: is concentrio engine-valve and surrounds the same" in spaced relation" thereto; i The arrangement of the ports and valve's'as providedacc'ordiii the present invention accoiiimoid a tes; erga nple, rig of subst'a'ntially the full area of one end Wall of t cornbiistionfchamber' or cylinder asintakeand ehhaut'portsj whereby a greater area a givenjcylinder is made'lavailablegfor p orting'then' could possibly be. attainedwithindividual poppet valves as has been convenis rrindfta define an annular V suns di g the exhaust ortia spaced" substantially concentric relatioii "t ret'o"; I Aft e 'iriner' and outer malrgins 5 of'nieaamis'sib err, the engiiiehaa or block is formed to define ap'airof concentric valve seats." An annular riing'valve," comprisingpreferably onlyametallic annulus, I is" providedto control the intake port, theisa me I being 1 adapted 'toj seat againstthe concentric"ivalvfe seats and surro'un 1 g the exhaust valve in radially spaced concen tric' "relation thereto.

Iri com and' 'val ve arrangementof the present'Qinvent n affords a engine couldbe'provided; at a maximum, with 1% i ch j,

diah et'er"exliaustand'intake ports; each 'afiordi ng a port areafof approxirn'ately ll'a square inches, According to thejples'eht"invention,for thesanie diameter cylinder, the exl' aust' porfl 'me'rely as "an' example andl not as a suggestd design","'could be '2 inches in diameter to afford a por" area'of 3.14 square inches'and the intake ,por t could ameterof 3 i'n'c'liest'o afford a port area of approximately 3.09 square inchesan increase of mo re than 250% in a over'conventional designs for the given cylinting' a decrease in cylinder volume for a given v porfiara to" accommodate increase in the compression ratio an'cl'po'wer of an engine,.assume that a port area of 1.23 square"i'nc'hes isdes'iredf From the above, it is obvi j c'o'nveritiona'l "simplified design: would nece s-, sarily mpioy'" two 'circular'po'rt's 1 A inches in diameter, which would necessitate acylinder diameter of ii fii inches. Accordiii'g tofhe"present invention however, the cenineh'ehi an'd' the 'anhu'lar 'intake' or admission port could dei 'diariiet er and of'appreirirnat'ely in "cylinder area over the conventional design. Accordingly, it is seen that 1am er. Analyzing this capabili ty in terms of aca irciilar' exhaust port would have a gliameter of 1%, 5

n inner diameiter of l /z inches: and an outerdi:

a. the present invention, by affording a novel port and valve arrangement, opens a new avenue of approach to internal combustion engine design to accommodate compression ratios heretofore unattainable. Also, the invention accommodates increased compression ratios in engines, such as the L-head engine previously referred to, that were regarded practically as being incapable of further power and compression ratio increases. Furthermore, the present invention afiords the above advantages in a particularly economical manner as will appear more fully hereinafter.

Having considered the aspect of engine design problems as regards compression ratios, it is of interest now to consider the problems involved in providing means for operating the valves. As noted above, the valves employed in conventional designs are poppet valves firmly biased to closed position by strong springs to be actuated to open position solely by means of engine operated cams and associated drive apparatus. Since present commercial engine design involves overhead valves set at an angle in the combustion chamber, it is apparent that many difiiculties are encountered in operatively connecting the valve stems to the conventional engine operated camshaft. The rocker arms and push rods employed in the operative connection or transmission between the overhead valves and the camshaft presents substantial inertia, which is a deterrent to proper valve opening and which is a factor that must be combated as regards valve closing by the use of very substantial or heavy valve springs. Even so, floating of the valves cannot be eliminated entirely, which is a serious disadvantage since valve opening and closing cannot be accurately controlled. To avoid this disadvantage, recourse may be had to double overhead camshafts, but the cost involved is so great as to negative practical recognition of the suggested solution.

In addition to suifering problems with respect merely to the connection of the valves and camshaft, designers also encounter problems of valve timing. A motor designed for high speed operation, if it is to be successful, must utilize a cam contour such as will hold the intake or admission valve open for a relatively long period in the cycle of engine operation. When a motor with such cam contour is running at slow speed, however, there is, at the start of the compression stroke of the piston, a reverse movement of air or the gaseous combustible mixture through the still open intake port due to the fact that the incoming column of the combustible mixture lacks sufficient momentum at that speed to resist or overcome the tendency to reverse flow, which disrupts the performance of the carburetor and results in a substantial loss of the combustible charge. This causes the engine to lack power and smoothness at lower speeds. On the other hand, a motor designed to run at slow speed will have a cam contour such as will open the intake valve for a relatively short interval in relation to the cycle of engine operation, with the result that the motor will lack power at high speed.

It is an object of the present invention to eliminate the problems of mechanical valve operation, connection of the valve to a camshaft, valve floating, cam contour and mechanical valve timing by mounting the intake or admission valve relatively freely, and entirely independently of mechanical actuating means, to accommodate intake valve actuation solely in response to fluid pressures acting thereon, whereby the valve is opened and closed solely in response to engine demands.

A further object of the invention is the provision of an intake or exhaust valve assembly constructed in accordance with the foregoing, wherein the intake or admission valve in its preferred form consists solely of a metallic annulus. Due to the fact that the intake port as described hereinbefore is an annular port, all that is required to close it is an annulus. Furthermore, since the valve is to be relatively freely mounted, no stem is required therefor. Accordingly, the present invention affords a particularly simplified intake valve for internal combustion engines.

According to the present invention, as will be appreciated from the foregoing, the engine head or block defines an annular intake port and a pair of concentric valve seats disposed, respectively, adjacent the inner and outer margins of the port. The annular intake valve is of a size to close the annular port and is adapted to seat upon the said concentric seats. Due to the fact that the port willbe of a relatively small radial dimension, and due to the seating of the valve on seats adjacent each margin thereof, the valve need be only a relatively thin washer. If desired, the central portion of the annulus may be rigidified by a web, but even so the annulus completely eliminates the heavy or bulky explosion resisting center and stem of the conventional poppet valve. Consequently, the annular ring valve is very light in weight, only a small fraction of a poppet valve of equal capacity. Furthermore, the valve when opened accommodates flow at both margins or peripheries thereof, whereby the valve need open only a limited extent to admit large volumes of gas.

Because of its light weight and short stroke, which reduces its inertia substantially to zero, the annular intake valve of the present invention, as incorporated in a four cycle internal combustion engine or the like, is ideally suited to actuation by means of the fluid pressures to which it is exposed. In a four cycle engine, the piston in its downward movement on the intake stroke tends to establish a lower pressure in the cylinder than exists in the intake manifold, whereupon the pressure in the manl fold is effective to open the valve to accommodate entry, as induced by the engine piston, of air or a combustible charge. On the upward compression stroke, the piston increases the pressure in the cylinder over that in the manifold, whereupon the valve is moved to closed position. As will be apparent, the valve will be maintained closed during the majority of the compression stroke, during combustion and during the expansion and exhaust cycles, whereupon the operation above described will be repeated. Due to the rapidity of piston movement, variations in pressure in the cylinder, to which the valve should respond, are quite sharp to insure proper actuation of the valve. Accordingly, it will be appreciated that the valve of the present invention depends for its operation solely on the pressure differential between the intake manifold and the engine cylinder. At low speeds, the valve will automatically adapt itself to a relatively short admission interval and the engine will idle or lug smoothly and with optimum power. Upon high speed operation, the gust or rapidly moving column of gas induced to flow at high speed past the intake valve, due to the high speed descent of the piston on its intake stroke, will have suflicient momentum to hold the valve open longer against compression than at low speeds, thus to duplicate in valve actuation the movement theoretically induced by the contour of an imaginary high speed cam. Accordingly, the valve of the present invention is operable solely in response to the demands of the engine to accommodate an exceptionally wide variation in engine speed and to afford smooth performance and optimum power at all speeds. In combination with a generally conventional mechanically actuated poppet type exhaust valve, the freely mounted annular intake valve provides an engine valve assembly assuring optimum engine performance.

In addition to opening a new avenue of engine design, accommodating increased compression ratios and affording an intake valve operable solely in response to engine demand, the present invention promotes highly economical overall engine design. Specifically, the present invention accommodates reduction in cylinder diameter, eliminates all mechanical actuating means for the intake valve and accommodates simplification of the exhaust valve actuating means, whereby the engine block and/ or head may be reduced in size and simplified very readily.

Itis-alsoan object of the present invention to'provide a highly simplified stop means in avalve and head construction as defined hereinbefore, wherein the stop means is disposed. in spaced relationto the seatof the annular ring valve positively to define limits-obvalvemovement.

A further object of the invention is the provision ofcombined stop and locating means; provided in accord? ance with the immediately foregoing, whereinthe means includes portions engaging the peripheral margin of the: annular valve tolocate orcenten the valve withrespect'toitsseats, and portions spacedfrom the valve seats andengageable withtthe surface of the valve to-defihetheopen position. of valve movement A still'further' object of. theinventionistheprovision, in avalve; and head construction-of thecharacter above defined, of' spring means of av relatively weak nature adapted at leasttoceunterbalance: the weight of the annular ring valve, the springmeansipreferablytbeing slightlystronger' than. the strength required: tocounterbalance: the. weight of the valve, whereby thespringmeans.- normally biases the. valve lightly toward: itslseat. While notv absolutely essential, the spring means:is;assistive:at.low\speed: starting-end does, not in any way interferewith optimum valveoperation-in response to engine. demands-at higher speeds.

In conventionahengine designs, .the poppet valves, as above noted, do notoperate. well at high speedtunlesssthe valyespringsare exceptionally stiff or strong; This stiff springing-leads-to substantial impact of the valve in1seat= ing ;;;and to rapid wear of the valve, valveseat, tappetand:v earn. In contrast, theringvalve of the present invention; due to its light weight, short strokeand large seating area, will not pound-against the seat, andthusiis not,subject:to= rapid wear; Furthermore, thevalvedoes not e-sulfer :limie tati ons'due to weight and stiff springing, sov that-the valve) is operableand positive in actionathigher. speedsithan' heretoforethought possible, While the,r in-g,-valve ofr'the invention willnot pound with; substantialimpact against. its seat and the stop means defining the open limilhOf: valvemovement, it may prove advisable insomedesignsto incorporate damping means for the valve; to eliminate the. possibility of pounding, particularlyinthevalye openw ing directiom and to insure; against vibration orfoscillas. tionof the valve. Int'his respect,;it-is;an; object; o f-the; present invention to-incorporate dampingmeanst ;.the annular valve in the valveand head construction described; bov spring. means referred .to hereinbefore, or speciallyzformed; and mounted. damping .means,

In, particular, it is an object of thepresent invention to. provide, in a head and valveuconstruction as above described, combined; damping,. centering stop;and spring; means for the annular valve- In apreferred;form such. combined means comprises a cam mountedfonrotation in ,the. header block means of the engine on tin-axisdisposedat right angles to the axis ofmovement -toathe annular, valve. The cam. presents a cam (surfacefacing and engageablewith. thevalve and curyedvto .define a. point of contact with the valve progressively spaced frorn the valve seat. Aspring operatively associated withrthe cam normally biases the hig hspot. thereof into,:eng age.- ment with thevalvetobias the. valve toward.itsclo'sed position. As the valve is opened, the camisrequired to, rotate against the force of thespring, thus dampingthe. opening movement of the valve. Whenthelow pointon the cam engages the valve, cam rotationnecessarily ceases, whereby the cam defines astoplimiting opening; movement of the valve. Also, the combined-means ;includes a mountingfor the cam, which mounting-may includeportions continuously engaging the margin of: the ,valve to center the valve with respect .to :itsgseat Thus, .a simple unit incorporates all the. controls desired for the; ring .valve. The cam,-v due A to: the -cam surfa'ce thereof, converts .:anytendency:.towardstpoundihg, vibration, or oscillation into a rolling actions and imparts Such means may taketheform, simply, of they 6 rotary movement to the valve as the engine" is running which distributes wear, keeps the valve and" its seat pollishedjand free of'carbon, andmaintains optimum seating. As Will be appreciated, despite reference hereinbefiore to combustible charges, the present invention has special adaptability to four cycle; internal combustion engines.

whether the same be of the spark or injection ignition type.

from or destroy the optimum configuration, of the combustion chamber, in either type of engine,.and'thus tend' to negative the advantagestobe'attained by the valve construction oftheinvention. In particular, it wouldappear that the presence of cams and the like protruding into the combustion-chamber would leadto' inefiicient ignition.

and explosion propagation. To'the contrary, it is. an object of the present invention to utilize'the cam meansas above described-forpurposes promotingmore efficient ignition and explosion propagation. Specifically, it is an object to soshape and locatethe cams, and to locate the ignition'means, the spark plugs or injectors, strategically. with respect to the-cams so that the explosionprogresses orpropagates with a swirling or whirlpool motion, or

some other desirable, propagation pattern. Ina preferred embodiment, three cams are provided in circumferentiallyv spaced relation in the combustion'chamber and a spark plug is disposed adjacent each cam' in non-radial'relationto the cylinder, each earn being provided with a facedefining a p'ortion'of a helix facing toward the. adjacent.

spark: plug, whereby, uponignition, the explosion propa:

gates in-a-somewhat helical'pattern toinsure complete and.

Otherobjects and advantages .ofthe present invention.

will become apparent in the following detailed description ofpreferred embodiments of the invention.

Now, in order to acquaint those skilled in the art --with my invention and the manner of making and using the invention, I'shall describein connectionwith the accompanying drawings, several preferred-embodiments of the invention and preferredmanners of making the .same.

In the drawings, wherein like reference numerals in.-

dicate like parts:

Figure 1 is a fragmentaryverti'ca'l cross section of'onea cylinder of an'internal combustion engine including a first embodiment of 'thehead and'.concentric arrangement of. the intake and exhaust valves of my invention, the viewbeing taken substantially on line 1--1 ofFigure 2;

FigureZ is a bottom view of the head and valvearrangement of the first embodiment of the invention, .the

view being taken substantially on. line 2-2 of Figure, 1;

Figure 3 is a perspective view'of preferred stopand centeringmeans as employed in the first embodiment ofthe invention;

Figure 4 is a view similar to. Figure 2 of .a second .embodiment of my invention;

' Figure -5is"an exterior"end'view.of one of-.the.cam means of the-Figure 4 embodiment of theinvention;

Figures 6, 7 and8 are inside end vie'ws'of one ofv the cam-means of-the Figure 4 embodiment of the invention,.. showing -thesequence ,of "cam movement upon. opening movement of the ring valve; and

Figure 9 isa fragmentary vertical section of the simplest preferred embodiment of the invention.

Referring now to the drawings, and particularly 'to Fig-I, ures :l and 2, thereisshown therein. a portion ofan in-..

ternal combustionenginecomprising arbl ock 10 defining. Fa '-cylir1de'n 12within"whicha piston'14 is'mounted for However, it would appear that the provision. of cam type means as described above would'tend to detract.

reciprocation in a conventional manner. An engine head 16 is attached to the block 10 and has therein a chamber 18, which together with the cylinder 12 defines a combustion chamber into which one or more spark plugs extend, suitably through the side wall of the head. For convenience, the engine block 10 and head 16 are referred to hereinafter generically as block means. The engine represented is a four cycle internal combustion engine of the spark ignition type, the piston thereof having the four usual strokes or cycles of intake, compression, expansion and exhaust.

The engine head 16, as shown, preferably comprises a metallic casting having cooling water passages 22 therein, as is conventional, an intake manifold or manifold extension 24, and an exhaust manifold or manifold extension 26, the manifolds 24 and 26 opening to the opposite sides of the head for communication, respectively, with generally conventional intake and exhaust manifolding covers (not shown), as will be appreciated by those skilled in the art. The exhaust manifold 26 is curved inwardly and downwardly within the block means or head 16 to terminate, in the embodiment disclosed, in a circular exhaust port 28 disposed substantially coaxially of the cylinder 12. About the port 28, the head 16 is machined or otherwise finished to provide a valve seat 31 The port 23 is adapted to be controlled by means of a conventional poppet type exhaust valve 32 including a stem 34 slidably mounted in the block means and a circular head 36 of a diameter larger than the port 28 and disposed to the cylinder side thereof, the head being adapted to engage the seat adjacent its peripheral margin to close the exhaust port. As is customary, the poppet valve includes an explosion resisting reinforced central portion 38. The valve stem 34 is slidably mounted in a bearing guide 40 which is press fitted or otherwise suitably secured in the block means or head in axial alignment with the cylinder 12. The valve stem 34 extends through the bearing guide 4t) to the exterior of the head 14 and adjacent its outer end carries an abutment in the form of a split conical washer 42 seated in a circumferential recess in the stem. The washer 42 defines a seat for a spring retainer 44, and a. pair of springs 46 and 48 are confined between the head 16 and the retainer 44, as is conventional with poppet valves, normally to bias the valve to closed position with the head 36 of the valve firmly engaging the valve seat 30. The exhaust valve is adapted to be positively actuated by any usual drive arrangement, such as from an engine driven cam shaft (not shown) through a push rod assembly (not shown) and a rocker assembly including a shaft 50 and a. tappet arm 52. en-

gageable with the upper exposed end of the valve stem 34. 7

As will be appreciated, the valve 32 is opened against the bias of the springs 45 and 58 by the drive means in timed relation to the movement of the piston 14 to accommodate discharge of the gaseous products of combustion, in the path indicated by arrows in Figure l, on the exhaust stroke or cycle of the piston 14. As thus far described, the construction. of the head. to afford the exhaust port and manifold, and the assembly of the exhaust valve and actuating means are generally conventional. except for the location of the port and valve substantially coaxially of the cylinder 12.

The intake manifold 24 is formed in the engine block means or head 16 to surround the portion of the exhaust manifold 26 adjacent the exhaust port 28 in generally annular form and is separated from the exhaust manifold by walls means and a generous water jacket 22, the jacket serving to cool the exhaust manifold and exhaust valve seat and to prevent undue transmission of heat to the intake manifold. The intake manifold 24 communicates with the combustion chamber 18 and cylinder 12 by means of an annular intake or admission port 54 disposed in radially spaced concentric relation to the exhaust port 28. The inner margin of the annular port 54 is spaced radially outward of the margin of the exhaust port and the outer margin of the port 54 is spaced radially inward of the peripheral Wall of the combustion chamber 18. Adjacent each margin of the port, the block means or head 16 is machined or otherwise finished to afford a pair of concentric circular intake valve seats 56 and 58. The intake port 54 is adapted to be controlled by an annular intake or admission valve having an inner diameter less than the inner diameter of the port 54 but greater than the outer diameter of the head 36 of the exhaust valve 32, and an outer diameter greater than the outer diameter of the port 54 but less than the diameter of the combustion chamber, the valve being adapted to engage the valve seats 56 and 58 to close the port 54. The valve 60 may comprise, simply, as is shown in Figure 1, a thin metallic washer or annulus of extremely light weight. At the outer margin of the valve 69, the peripheral wall of the combustion chamber 18 is spaced from the valve, or is formed to be spaced substantially from the valve, to accommodate flow of gases from the intake manifold past both margins of the valve. Accordingly, the valve need open only a short distance to accommodate maximum capacity flow through the intake port 54. Due to its short stroke and light weight, the valve is ideally suited to actuation solely in response to engine demands as a function of the pressures acting thereon, which is a primary object of the present invention.

The intake valve 60 is disposed within the engine cylinder and/ or combustion chamber entirely independently of the exhaust valve 32 and no means are provided for mechanically actuating the valve, the same being at least relatively freely mounted for movement in response to pressures acting thereon. In the case of a four cycle internal combustion engine, the valve is thus caused to be moved on the downward, intake stroke of the piston 14, as a result of the pressure in the intake manifold 24 exceeding that in the cylinder 12 and combustion chamber 18, to open the valve to accommodate entry of fresh gases to the cylinder and chamber. Upon the upward compression stroke of the piston, the pressure in the combustion chamber exceeds that in the intake manifold and the intake valve is closed to accommodate full compression of the gases. Upon explosion of the gases and the expansion stroke of the piston, the valve is held to its seat by the high pressure in the cylinder and combustion chamber, and also upon the upward exhaust stroke of the piston M due to the relatively high pressure in the cylinder. Since the valve 63 seats uniformly on two seats and bridges only a relatively short radial space, the valve need be only a relatively thin washer and yet will readily withstand the shock of the explosion. At low speed, the valve 60 will automatically be actuated to provide a relatively short open interval thus to accommodate entry of the proper charge for eflicient engine operation at that speed. At higher speeds, the valve will automatically be opened in the manner above described, but the inflowing column of gas will have such momentum as to retain the valve open a relatively long interval after the compression stroke commences, thus to insure a complete charge of gas in the cylinder necessary to high speed operation. At any engine speed, the valve will be responsive to the pressures acting thereon to open and close exactly in conformity to the demands of the engine for optimum performance. Since the valve is light weight and has a short stroke, it has substantially no inertia and can build up little momentum and, therefore, is immediately responsive to critical variations in the pressure differential between the intake manifold 24 and the cylinder l2 and combustion chamber 18. in short, the valve will operate at substantially any given speed in accordance with the valve operation theoretically produced by an engine operated cam specifically designed for that speed. Accordingly, it is to be appreciated that the valve 60 of the present invention operates in optimum timing with the engine piston to insure desired engine performance at all speeds.

W e he u r al e 69: 1. e nv ti n, bove noted, has little inertia and. is operable, at substantially all engine speeds in an optimum manner, I- prefer to. improve still further on the arrangement as above d scribed by providing springmeans, indicated generally. at 62, at least to counterbalance the weight of the annu: lar ring valve and preferably to bias. the. same slightly toward closed position, but not necessary to a completely closed position. Counterbalancing the weight of the valve reduces its inertia, and normal disposition of the valve adjacent or lightly in engagement. with its seats assists in proper valve operation at. very lowspeeds and in starting of the engine. In the Figure l embodiment of the. invention, the spring means 62 comprises a plurality of small: tension springs 64 connected to. the valve 60 by means of tabs 66formedintegrally. withthe valve, and to hooks 68- formed integrally with the. head 16 within the intake manifold 24. The springs64, together, are of a strength only slightly inexcess ofathe. strength required to counterbalance-the valve 60 and, accordingly, biasthe valve toward its seats and, preferably, lightly into engagement with its seats, thus to afford the advantages noted above with respect to engine operation. While the springs afford assistance to valve operation, thev valve nevertheless is substantially freely mounted in the engine. forv movement solely in response. to engine demands, since the spring are not strong enough to negativeor in any way detract from the above described optimum engine operation.

As will be appreciated, the annular ring valve 60 cannot. be entirely freely mounted inthe cylinder, since the'valve, if notrestricted, would tend to travel with the engine piston. However, the valve must not be constricted, since it is necessary thatthesamebe free to move independently in response to engine demands. In other words, means mustbe provided to limit opening movement of .the valve without otherwise interfering with the valve. To this end, I provide stop means, indicated generally'at 70, disposed in axially spaced-relationto 'the admission port 54 to limit opening movement of the annular admission valve! Also, since space is provided according to the invention at-both margins of thevalve to accommodate maximum admission of gases, it.is preferable to provide locating. means to center. the valve .with respect to its seats. In the embodiment of-the invention.shoWninFigures l-to'3, the stop means and. locatingmeans are incorporated in a single assembly comprising, as particularly shownfin Figure '3, astop. member,72t and a locating memben-74; Preferably, a plurality of..such.assemblies. areprovided, asihdicated at 70 in Figure 2, in circumferentially spaced relation about the. combustion chamber. The. member, 72 comprises a boltsadapted to be threaded into. a tappedbore. provided in the. peripheral wall 'ofthe.combustionchamber. to. extendsubstan'tially radially from the wall into. the chamber and into. the .path of movementofthe valve,60.'. Thebolt. is. provided. with. a head and the. head. is preferably machined to present a. flatstop. surface.76.-. for engagement by. the. valve. to. limit openingmovement. of. the valve. The locating member 74,. comprises .aItubularspacer. ele: ment adapted for the passagetherethrough of the bolt and having a radial, tab-like. extension. 78 presenting. a rearward surface. conforming substantiallyv to. the configurationof :the. combustionchamber lssand, a flat fOI'e: ward :face. engageable with v the outer. peripheral margin of the valve 60; In assembly, the locating. members 74\ are disposed in the combustion. chamber. in general align.- ment with, the, respective radial bore: adapted. for .the receptionof a stopmember 72. The .valve.60 isathenplacedin thechamberlS, the members .74.being.ofjsuch-.length as to have the fiat surfaces thereof. disposed immediate lyadjacent theouter margin ofthevalve to guide the valveto its seats substautiallyin c entered;.rel ation; tothe.

d issi n Pa t- 4.. e a em era re; he -i ted:

74; and: threadedv into the respective bore. in the. chamber. and tightened; to. dispose thesurface 76v thereof in. facing relation to the lower surface. of thevalve, whereupon the. assembly is completed, the valve is properly positioned. in the chamber 1.8. the valve is centered with. respect to its seats, and positive limits of valve. movement; are provided, all in a, highly economical and practical manner.

From the, foregoing, it will be appreciated that, the, present invention affords a particularly advantageous; valve arrangement for internal combustionengines and? the like, wherein valve operation iscompletely and. per.- fectlyresponsive to engine demands, even though those. demands vary widely from low. to high speed operation, rather than being dependent upon and subjectto: the serious shortcomings of mechanical drive meansand me chanical design of cams and the like, which can be of. optimum efiiciency for only one speed.- Also, the valve, due to its independency, is not subject to the speed.- limitations imposed; upon mechanically operated; valves inconventional designs, thus openingthe way tohigher. speed engines than heretofore contemplated. Furthermore, the concentric arrangement of the valves accommodates substantial increases in compression ratios by accommodating a greater port area. to cylinder. arearatio -than heretofore possible, with conventional designs,

A few examples of this capability have been pointed out in the introductory portion of the present specification, Torepeatone of; these examples, assume the desired condition of intake and exhaust ports having-anarea, of; 1.23 square inches. In a conventionalidesign, two circular ports, each-1% inches in diameter would have-to be provided, which would resultg in-a cylinder diameter of-approximately 3%, allowing ,4: inch clearances, Ac-

cording to the, presentinvention, the exhaust-port wouldpresentinvention, neednot be. of as great adiameter as.

that. of theco mbustion chamber. adjacent. the valve, but could,;for example, be .ofthe same diameter as the outer. diameter of the. valve. This arrangement would accommodate-a total decrease. in cylinderarea overconventional designs .of.approximately.63%. From these. figures, it is.

apparent that the presentinvention accommodates v tree mendous increases in compression ratios and horsepowep output in internal combustion engines.

Inview of the. capability of the present inventionto afford very substantial increases in. compressio-nratios,

engine power andenginespeed, it is contemplated that. present ignition systems may' prove inadequate to cope; In view of-this factor, I.

with the. advances aiforded. prefer to incorporate a plurality. ofspark. plugs 20,. or,. fuel injectors, or. the. like, ineach combustion. chan1-.v ber,rather than the single unit conventionally provided.

Forexample, as shown in Figure 2, a pair. of, ignition.

units or spark plugs 20 may be provided .in diametrically opposed relation, thesame extending substantially radiallyinto the combustion chamber through the. side walls of the. block. means or head 16.

In. addition to. affording, substantial advantages with respect to engine operation, engine speed, and compression ratios, the. present invention accommodates and. provides substantial economies in the design, manufacture. and assembly-of the engine block means. Normally, it would be. expected. to. obtain substantial advantages .in engine and valve. operation and increases in compression ratios only bysubstantially increasing the. cost and com.-

in the. c han1ber through the respective tubular. men l fli 75 ;p1exityof'theengine. Directlythecontrary is true with the present invention, since the advantages afforded by the invention are all accomplished as a result of a very high degree of simplification. Since all mechanical operating means for the intake valve are eliminated, it is obvious that a substantial saving is achieved with respect to the mechanical components and assembly steps required in the manufacture of an engine. Secondly, the capability of the invention substantially to increase compression ratios with highly simplified piston and com bustion chamber designs, eliminates many of the costly and complicated manufacturing steps invol ed in making most of the present day high compression engines. Third, the capability of the present invention to reduce combustion chamber and cylinder size affords a further saving in material, and fourth, the provision of only a single valve to be mechanically actuated accommodates simplification and ready assembly of the actuating means for this valve. Furthermore, the total result of the foregoing reductions in cost and complexity is to reduce the size and intricacy of the engine block means, as including the block it? and head 16, thus to afford an engine having greater capabilities than conventional engines and at the same time one that is much more economically produced than previously proposed designs. Accordingly, it is to be appreciated that the present invention affords substantial advances in engine design, particularly with respect to engine operation, power, performance, and economy.

As pointed out hereinbefore, the annular ring valve 66 of the invention is light weight and has a short stroke, whereby its inertia is reduced nearly to zero and whereby it cannot build up substantial momentum. Due to the fact that the valve has double seating at 56 and 58, the same will not slam closed and little wear of the valve seats and valve will. be occasioned. However, in the opening direction, it may in certain instances be desirable to provide means eliminating any possiblity of valve vibration and slamming or substantial impact of the valve against its stops. In Figures 4 to 8, I have shown preferred means for accomplishing this result, wherein the means afiords, in a single assembly, stop means of the nature previously drescribed, spring means of the nature previously described, locating or centering means of the nature previously described, means for damping movements of the valve, and means affording a predetermined pattern of explosion propagation to insure efiicient ignition of the fuel in thc combustion chamber. The embodiment of the invention as shown in Figures 4 to 8 is very similar to that previously described, with the exception of the combined means provided therein, and accordingly, parts similar or identical to those previously described have been indicated by the same reference numerals.

In Figures 4 to 8, the combined means or damping means of the invention is indicated generally at 3'0 and a plurality of the means or assemblies are provided in circumferentially spaced relation about the combustion chamber. Each unit comprises a mounting member in the form preferably of a split sleeve inserted in and extending through a radial bore provided in the block means or head 16. A cam member 84- including a shaf portion 86 is rotatably mounted in the member 82 with the cam portion thereof disposed within the engine combustion chamber. The shaft portion 86 is preferably provided with a tapped bore therein opening to the rear ward end thereof and adapted for the adjustable reception of a set screw 38, the set screw assuming, when set. a fixed relation to the shaft and cam. To the exterior of the block means or head 16, a clamp 90 is secured, suitably by a screw 92, to the extending portions of t.e split sleeve 82, and the clamp includes a boss from. which a pin 9-4 extends. The pin 94 constitutes a mounting for the free or outer end of a fiat, helical, torsion spring $6, in the nature of the watchmakers hair spring, the other end of which is connected to the set screw 83,

12 whereby the spring is effective to exert a rotary force on the cam 84. As both the clamp and the set screw 38 are adjustable, the rotary force exerted on the cam 84 by the spring 96 may be varied quite widely, the more readily eifected adjustment being that of the set screw 33.

The cam 84 presents a first cam surface 93 opposed to the face of the ring valve 60 and engageable therewith. The surface 98 is formed to present, as the cam rotates counterclockwise as viewed in Figures 6 to 8, a point cngageable with the valve disposed progressively further away from the valve seats, thus to accommodate valve opening. When the cam is moved to dispose the lowest point on the surface 98 thereof in engagement with the valve, the cam cannot rotate further and thus constitutes a stop defining the open limit of valve movement, as shown in Figure 8. Accordingly, the unit 80 is first the stop means of the character hereinbefore defined with reference to numeral 70. The spring 96, as will be a preciated from Figures 5 to 8, normally biases the cam 84- in a clockwise direction as the same is viewed in Figures 6 to 8, thus to dispose the high point of the cam surface 98 in engagement with the valve as shown in Figure 6. The cumulative effect of the springs 96 of the three units 80 is to only slightly more than offset the weight of the valve 59, whereby the valve is counterbalanced and lightly biased toward its seat. Accordingly, the unit 80 is secondly a spring means of the nature previously described with reference to numeral 62). Furthermore, the adjustability of the spring 96 accommodates variations in valve responsiveness by the simple expedient of an adjustment from the exterior of the engine. With respect to centering the ring valve 60 in relation to its seat, the mounting members 82 may each present a face to the interior of the combustion chamber engageable with the outer peripheral margin of the valve to center the same in much the same manncr as described with reference to numeral 74.

Upon downward movement of the valve 60 on the intake stroke of the piston as hereinbefore described, the valve will engage the cam surfaces 98 and cause the cams 84 to rotate against the bias of the springs 96. Thus, the springs 96 will cushion the valve and prevent substan tial impact of the valve with its stops, and will eliminate any possibility of valve vibration. Also, the rotary movement of the cams transforms the straightline movement of the valve to a smooth rolling action to eliminate slamming. Accordingly, it is to be appreciated that the units 80 damp the ring valve 60 to insure optimum operation thereof. Furthermore, the rotation of the cams imparts a rotary impetus to the valve to cause the same to rotate by small increments within the engine, which rotary movement eliminates the possibility of one cam constantly engaging the same point on the valve and wearing a pocket therein, results automatically in cleaning of the surface of the valve and the cam surfaces 98 to insure optimum valve operation, and renders the valve automatically self-cleaning and self-polishing, the valve in turn polishing its seats and the cams to insure optimum performance and uniform wear of the valve.

In addition to the surface 98, the cam 84 is curved gen erally laterally of the curvature of the surface 93 to define a second cam surface 100 disposed generally at right angles to the plane of the valve 60. In this embodiment of the invention, the spark plugs 20, which may suitably be of the same number as the units 80, are each disposed adjacent a unit bi preferably in non-radial relation to the cylinder and in non-parallel relation to the respective unit, with the inner end thereof opposed to the cam surface lttil of the respective unit 80. The cam surface 109 is formed in a predetermined manner to coact with the spark plug 20, fuel injector, or other ignition means, to impart a desired propagation pattern to the explosion ignited by the ignition means. For example, as is shown in Figure 4, the cam surface 100 of each cam 84 may be u v d t defi e a po i n a hel sal P nmhax a t focus atthe"center of theengine plis't h, andtlieisfphrjf plug' 20 is opposedto such surface, w re yf i giz Of h p weak h m 1 ,lblgfdi it'fi. the combustion chamber, a helical, "swirling, or g V pool propagation pattern is imparted to theexplosion'fto insure proper, complete and efificient ignition andexpan sio'n'of the combustible charge. Accordingly, m eting, ing 'means,'instead of detractihgfrombpti fliim chajmb design, actually contributes to thefoveifall'i designf affords another particular advantage 0f the present inf vention. Also, the provision of a plurality ofignition de vices insures uniform, instantaneous'i iiit'ionand sion of the fuel in the 'co'rnbustionbharn In view of the foregoing, itfis to biejappreciatedthat the damping m s 01 pr sen n ent on, fi fdsi substantialiadvantages in conjunction with the conee ic' valve arrangement of the inventio'n and incorporates in, a single and economically produced unit the several op'- crating characteristics enumerated hereinbefo'rq prin pe mp flexibility qfft f nih lcft valve and accommodates wider openihg oflthe valve th permanently located stops. Also, the adjustabi ll y of springafiords the distinct possibility oi alterihgthe speed and torque characteristics of the' engine by a justment at the side of the engine blocl; means. "Referring now to Figure 9, aisimplifiejid embodiment, of the invention is shown wherein all splrihgsand 'da 1'1'1 pe n j have been eliminated. The embodime'n isf'gen' ally similar to that of Figure 1 and partsisimilapto'th pr viously described have been indicated by th' sam reije ence' numerals. In addition to elimination 'of th p U means, the stop means 70 has been simplified, the comprising merely a plurality of pegs ori'pins '10 pres fitted or otherwise secured in theen'gin'e bl' h'ead'lo to project radially into the p p w thejannular ringvalve 60. A degree o f'cente g ingot the valve may be attainedwith these byjpr viding a stepped outer end portion onthe pins, as is she The annular valve 60 in this embodimeht'otthe iinven' 'on comprises, instead of a thin flat washer'as previously d escribed, an integral annulus including a plate portion and a reinforcing web 106, Thewel lqfi delcreiise 'm width from the plate portion 104into the ahnular adm' si'onl port 54. to serve the triple functionsiof 'reintor thevalve, at least partially centering the valve 60 W1t respect to its seats 56 and 58, and defininga smootlfpa 'Q 1 ti 1 1 4 i for the inflow of gases to eliminatelanyobs flow and toinsure against undue turh l iv. coming stream of gases. t

1:4 nve to in a r sh ae rssiq tat uir teased Horsep'owefcaiib hit i Y ticgn; it will a d what I regard, t9 be preferred. df'that ,lye. asse nbly for, it

a. v t 2? We; h re J said adm ssion valve being inde; exhaust valve and a least relatively eathere to re 5 s 2. te" P .tions in; the 'cy t gegtw'ta whi'hgass' ociatd.

' valv'e assembly. for. four g at, l ast one p 1 in. response, to; e P e l t s n tht- Wa sh databa es? en ine rhe lieg e 11a yl nder k eans openi I djnth'el'blok From the foregoing, it will be appreciated that the present invention, in its various embodimets, aifords substantial advantages in internal combustion eh 'ne sign, in increased compression ratios and power output, inoptimum valve operation and in high speed pera of the valve. While the foregoing embodiments; ha

been described principally in relationto tion engines of the spark ignition type, it is clear that invention is very advantageously employed injinj type engines. To the present, four'cycle Diesel engmesi have not been able to compete with the gasoline engine in light weight machinery due to aninability tofintro adequate air into the cylinders while maintainmgt e high compression ratios necessary to corn'pre'ss iori'fig tion. The ability of the present invention to solve'such problem is apparent. Furthermore, the p'reserit inven is not limited in application to internal combusti gi nes, but has complete applicability tofcomp essors, positive displacement pumps and thelike, "sucli a's "a'two cycle pump including a high pressure responsiveoutleh valve and the admission valve of the' invehtioti di'sp' in concentric relation to the outlet valve.

'In addition, the invention has been describedherein before with reference to simplified engine d Y 'b chamber design, which of course, is one adya tage of I take, manifoldfin th block rneans and nuintahe port .111,

h mantis, 4 and spring me th 19 1 mam i lrv qllnt i ll aidt xh nst. pc n pa ed 1 concentric relation ,theretp and, establishing communicatignbetweenthe intake manifoldand the cylinder, avalve.) assemblycomprisingan, exhaust valve .having a headto. close, the exhaust port, an intake valve comprising a rela tively' thin annulus surrounding said-exhaust valve head in spaced concentric-relation thereto to close thepint ak e port, said intake valve being at least rel a'tively freely m' unteq in' the "cylinder indperideiitiy' or said "exhaiist' valve'to the cylinderside of the in take port ta'mdve in re ponse to .VeIfi I Q S, Q,P T$}-1Ie differential b tween i jm'afiifo a are t fjcylipdeefwheieb ji t opened and clesed isolelyfingaecord I i 15 block means and said intake valve normally to bias said intake valve lightly toward the intake port.

5. In an internal combustion engine or the like having block means defining at least one cylinder, an exhaust port in the block means opening into the cylinder, an intake manifold in the block means, and an intake port in the block means rrrounding the exhaust port in spaced concentric relation thereto and establishing communication between the intake manifold and the cylinder, a valve assembly comprising an exhaust valve having a head to close the exhaust port, an intake valve comprising a relatively thin annulus surrounding said exhaust valve head in spaced concentric relation thereto to close the intake port, said intake valve being at least relatively freely mounted in the cylinder independently of said ex haust valve to the cylinder side of the intake port to move in response to variations in the pressure diiferential between the manifold and the cylinder, whereby the intake port is opened and closed solely in accordance with engine demands, and stop means mounted on the block means within the cylinder in spaced relation to the intake port to limit opening movement of said intake valve with respect to the intake port.

6. In an internal combustion engine or the like having block means defining at least one cylinder, an exhaust port in the block means opening into the cylinder, an intake manifold in the block means, and an intake port in the block means surrounding the exhaust port in spaced concentric relation thereto and establishing communication between the intake manifold and the cylinder, a valve assembly comprising an exhaust valve having a head to close the exhaust port, an intake valve comprising a relatively thin annulus surrounding said exhaust valve head in spaced concentric relation thereto to close the intake port, said intake valve being at least relatively freely mounted in the cylinder independently of said exhaust valve to the cylinder side of the intake port to move in response to variations in the pressure differential between the manifold and the cylinder, whereby the intake port is opened and closed solely in accordance with engine demands, spring means operatively associated with the block means and said intake valve to counterbalance the weight of said intake valve and normally to bias said intake valve lightly toward the intake port, and stop means carried by the block means within the cylinder in spaced relation to the intake port to limit opening movement of said intake valve with respect to the intake port.

7. In an internal combustion or the like having block means defining at least one cylinder, an exhaust port in the block means opening into the cylinder, an intake manifold in the block means, and an intake port in the block means surrounding the exhaust port in spaced concentric relation thereto and establishing communication between the intake manifold and the cylinder, a valve assembly comprising a positively driven exhaust valve having an operating stem slidably mounted in the block means and a head secured to said stem to close the exhaust port, an intake valve consisting of a thin annulus surrounding said exhaust valve head in spaced concentric relation thereto to close the intake port, said intake valve being at least relatively freely mounted in the cylinder independently of said exhaust valve to the cylinder side of the intake port to move in response to variations in the pressure differential between the manifold and the cylinder, whereby the intake port is opened and closed solely in accordance with engine demands, and a plurality of circumferentially spaced stops extending radially inward from the peripheral wall of the cylinder in spaced relation to the intake port to limit opening of said intake valve.

8. In an internal combustion engine or the like having block means defining at least one cylinder, an exhaust port in the block means opening into the cylinder, an intake manifold in the block means and an intake port in the block means surrounding the exhaust port in spaced concentric relation thereto and establishing communication between the intake manifold and the cylinder, a valve assembly comprising an exhaust valve having a head to close the exhaust port, an intake valve surrounding said exhaust valve head in spaced concentric relation thereto to close the intake port, said intake valve being at least relatively freely mounted in the cylinder to the cylinder side of the intake port to move in response to variations in the pressure differential between the manifold and the cylinder, whereby the intake port is opened and closed solely in accordance with engine demands, and locating means mounted on the block means and at least partially engageable with said intake valve to center said intake valve in relation to the intake port and to define a path of intake valve movement related to the intake port.

, 9. In an internal combustion engine or the like having block means defining at least one cylinder, an exhaust port in the block means opening into the cylinder, an intake manifold in the block means and an intake port in the blockmeans surrounding the exhaust port in spaced concentric relation thereto and establishing communica tion between the intake manifold and the cylinder, a valve assembly comprising an exhaust valve having a head to close the exhaust port, an intake valve surround ing said exhaust valve head in spaced concentric relation thereto to close the intake port, said intake valve being at least relatively freely mounted in the cylinder to the cylinder side of the intake port to move in response to variations in the pressure differential between the manifold and the cylinder, whereby said intake port is opened and closed solely in accordance with engine demands, and a plurality of centering and stop units disposed in circumferentially spaced relation about the peripheral wall of the cylinder, said units each including centering portions engageable with the marginal edges of said intake valve to center said intake valve in the cylinder and with respect to the intake port, said units each including stop portions projecting radially inward from the peripheral wall of the cylinder in spaced relation to the intake port engageable by said intake valve to limit opening move-- ment of said intake valve.

10. In an internal combustion engine or the having block means defining at least one cylinder, an exhaust port opening into the cylinder, an intake manifold in the block means and an intake port in the block means surrounding the exhaust port in spaced concentric relation thereto and establishing communication between the intake manifold and the cylinder, a valve assembly comprising an exhaust valve having a head to close the exhaust port, an intake valve surrounding said exhaust valve head in spaced concentric relation thereto to close the intake port, said intake valve being at least relatively freely mounted in the cylinder to the cylinder side of the intake port to move in response to variations in the pressure difierential between the manifold and the cylinder, whereby the intake port is opened and closely solely in accordance with engine demands, and spring biased cam means movably mounted on the block means and operatively associated with said intake valve normally to bias said intake valve toward the intake port, the spring means of said cam means being eflective to exert a force on said intake valve only slightly in excess of that required to counterbalance the weight of said intake valve, whereby said intake valve when moving in response to engine demands is lightly clamped by said cam means.

11. In an internal combustion engine or the like having block means defining at least one cylinder, an exhaust port in the block means opening into the cylinder, an intake manifold in the block means and an intake port in the block means surrounding the exhaust port in spaced concentric relation thereto and establishing communication between the intake manifold and the cylinder, a valve assembly comprising an exhaust valve having a head to close the exhaust port, an intake valve surrounding said exhaust valve head in spaced concentric relation thereto to close the intake port, said intake valve being at least relatively freely mounted in the cylinder to the cylinder side of the intake port to move in response to variations in the pressure differential between the manifold and the cylinder, whereby the intake port is opened and closed solely in accordance with engine demands, a plurality of cams extending radially inwardly from the peripheral wall of the cylinder, said cams being rotatably mounted on the block means, and torsion spring means operatively associated with each of said cam means normally to rotate the same in a given direction, said cams each including a cam surface engageable with one surface of said intake valve and curved progressively to accommodate movement of said intake valve away from the intake port upon rotation of said cams against the bias of said spring means, said spring means normally biasing said cams to move said intake valve toward the intake port, said cams damping the movements of said intake valve.

12. In an internal combustion engine as set forth in claim 11, means associated with said cams and said spring means accommodating adjustment of said spring means to vary the damping characteristics of said cams.

13. In an internal combustion engine as set forth in claim 11, ignition means adjacent each of said'cams, each of said cams including portions adjacent the respective ignition means to impart a predetermined propagation pattern to the explosion ignitedby said ignition means.

14. An admission and exhaust valve assembly for internal combustion engines and the like having at least one cylinder, comprising an exhaust valve having a valve head, an admission valve disposed concentrically about and surrounding said exhaust valvevhead, said admission valve being independent of said exhaust valve and being freely mounted to move in response to pressure'variations in the cylinder with which associated, and locating means at least partially engageable with said admission valve to locate said admission valve in predetermined relation to the cylinder.

15. An admission and exhaust valve assembly for in ternal combustion engines and the like having at least one cylinder, comprising an exhaust valve having a valve head, an admission valve disposed concentrically about the surrounding said exhaust valve head, said admission valve being independent of said exhaust valve and being freely mounted to move in response to pressure variations in the cylinder with which associated, and at least one locating and stop unit including a portion engageable with the edge of said admission valve to locate said admission valve in predetermined relation to the cylinder and a stop portion engageable with one surface of said admission valve to limit movement thereof.

16. An admission and exhaust valve assembly for internal combustion engines and the like having at least one cylinder, comprising an exhaust valve having a valve head, an admission valve disposed concentrically about and surrounding said exhaust valve head, said admission valve being independent of said exhaust valve and being freely mounted to move in response to pressure variations in the cylinder with which associated, and spring biased cam means operatively associated with said admission valve normally to bias said admission valve in one direction, said spring biased cam means being effective upon movement of said admission valve in the opposite direction lightly to damp the movement of said admission valve.

References Cited in the file of this patent UNITED STATES PATENTS 713,147 Power Nov. 11, 1902 1,501,038 Brooks July 15, 1924 1,555,804 Konar Sept. 29, 1925 FOREIGN PATENTS 152,847 Germany Apr. 3, 1903 11,065 Great Britain May 9, 1912 15,734 Great Britain July 8, 1913 

